RE: FPU precision & signal handlers (bug?)

Eric Ries
2002-03-04T23:32:26Z

> -----Original Message-----
> From: Alan Cox [mailto:alan@lxorguk.ukuu.org.uk]
> Sent: Monday, March 04, 2002 2:38 PM
> To: Eric Ries
> Cc: linux-kernel@vger.kernel.org
> Subject: Re: FPU precision & signal handlers (bug?)
>
>
> Think about MMX and hopefully it makes sense then.

Yes, I think I understand why this is the case presently.

> > strikes me as kind of a hack. Why should the signal handler, alone
> > among all my functions (excepting main) be responsible for blowing
> > away the control word?
>
> Right - I would expect it to be restored at the end of the signal handler
> for you - is that occuring or not ? I just want to make sure I understand
> the precise details of the problem here.

Yes, my belief is that the kernel undoes the FINIT changes by restoring the
FPU state after the signal handler returns.

Eric